Relay.



B. G. DUNHAM.

RELAY.

APPUCAHON HLED OCT. I2, 915.

1 ,2 1 0,6 1 7 Patented Jan. 2, 1917,

Fig.

Fig. 2. Fig. 3.

-/n ven/or: Ber! C. Dun/7am 1 UNITED STATES PATENT OFFICE.

BERT G. DUNHAM, OF HAWTHORNE, JERSEY, ASSIGNOR, BY MESNE'ASSIGN- MENTS, TO WESTERN ELECTRIC COMPANY, INCORPORATED, A CORPORATION OF NEW YORK.

RELAY.

Specification of Letters Patent.

Patented Jan. 2, 1917.

Application filed October 12, 1915. Serial No. 55,501.

To all whom it may concern:

Be it known that I, BERT G. DUNHAM, a citizen of the United States, residing at Hawthorne, in the county of Passiac and State of New Jersey, have invented certain new and useful Improvements in Relays, of which the following is a full, clear, concise, and exact description. W

This invention relates to relays, and more particularly to what are known as slowacting relays, such as are used, for example, in two-wire step-by-step automatic telephone exchange systems. In systems of this character a pair of such relays is ordinarily associated with each selector switch, being maintained energized by impulses from the steppin relay as it is intermittently 0perated y the sender during the setting of the selector. One of these relays receives impulses from the front contact of the stepping relay to hold open the selector release circuit and the other from the back contact of such relay, and when the sender restores and maintains the stepping relay energized, such relay after a short interval becomes deenergized and effects the changeover operation to initiate the trunk hunting operation of the selector. One of the methods of causing these relays to release their armatures slowly is to place a jacket of copper around the relay winding. This invention provides a relay which will hold up its armature for a sufiicient interval after its circuit is opened without the necessity of such jacket or with a jacket relatively small as compared with slow relays heretofore employed.

In accordance with this invention, the retractile spring for the armature is so connected thereto and to the relay frame that it exerts a minimum retractive force when the armature is against the core, which force increases as the armature moves away from the core, when the magnetism dies down sufficiently to permit such force to become effective. The free end of the retractile spring may be connected by a suitable link with the armature, the points of connection of said link with said spring and armature being substantially in line with each other and with thepivotal point of support of the armature when such armature is attracted.

Referring to the drawing, Figure 1 is a side elevation of a relay constructed in accordance with this invention with the armature in its retracted position; Fig. 2 is an cover 10 carrying ears 22,

end elevation thereof; Fig. 3 is a partial side elevation with the armature in its attracted position; and Fig. 4 is a perspective view of the relay with the armature in its retracted position.

The relay comprises the usual core and winding, the winding being protected by a 23 at its forward end between which the armature 15 is pivoted at 18. The relay winding terminals are shown at 11. The contact with which the armature is adapted to engage when retracted is shown at 12, the return for this circuit being furnished by spring 18. Spring 13 is secured to the cover 10 by screws 14. The retractile spring 16 for the armature 15 is also secured by these screws to the cover 10. This spring extends below and parallel to the cover and has a perforation 19 in its free end with which one end of a link 17 engages. The other end of this link engages with a notch 20 in the upper end of the armature. The location of the perforation 19, the notch 20 and the pivot 18 of the armature is such that when the armature is in its attracted position, as shown in Fig. 3, the force of the spring 16 exerted through the link 17 is partially neutralized, since it will be seen that the points of connection of the link with the spring and with the armature are substantially in line with each other and with the pivotal point of the armature. The pivotal point 18 is slightly inside of a vertical line connecting the perforation 19 and notch 20. The result of this construction is that when the circuit of the relay is opened, the force exerted by the spring 16 will not be strong enough at first to overcome the magnetism in the core. After an interval, however, this magnetism dies down and the slight force exerted by the spring 16 is suflicient to cause the upper end of the link 17 to cause the armature to begin to fall back. As this movement progresses the effective force of the spring increases the retractive movement being arrested when the contact 21 on the armature 15 engages the contact spring 12.

If desired, a relatively small jacket of copper may surround the winding to aid in retarding the release of the armature.

What is claimed is:

1. A relay comprising a. core, an energizing winding thereon, a pivoted armature,

and means for retracting said armature comprising a spring associated therewith and constructed and arranged to exert a Ininimum retractive force when the armature is in its attracted position.

2. In a relay, the combination With the frame, a core, a Winding thereon, an armature pivoted to said frame, a retractile spring for said armature mounted on said frame, and a link connecting said spring and armature, the points of connection of said link With said spring and armature being substantially in line With each otherand With the pivotal point of support of the armature when the same is attracted.

3. In a relay, the combination With the frame, a core, a Winding thereon, an armature pivoted to said frame, a retractile spring for said armature mounted on said frame, and a link connecting said spring and armature, the points of connection of said link With said spring and armature and the pivot of said armature being so arranged that they approaoh alinement when the armature is attracted.

In Witness whereof, I hereunto subscribe my name this 7th day of October, A. D. 1915.

BERT s. DUNHAM.

copies of this patent may be obtained for five cents each, by addressing the Washington, D. 0.

Commissioner of Patents. 

